1. Field of the Invention
The present invention relates to a copying apparatus, and in particular, to a copying apparatus in which an original and a three-dimensional object disposed on a platen glass can be copied.
2. Description of the Related Art
In a copying apparatus, in which light is illuminated onto an object to be copied which is disposed on a platen glass and the reflected light is exposed onto an image recording material (photosensitive material) so that copying (image recording) is effected, the exposure device is formed by a light source, a reflecting mirror and a plurality of lenses. In this type of copying apparatus, the object to be copied which is disposed on the platen glass is covered by a platen cover. Light from the light source is illuminated onto the covered object to be copied. Among the illuminated light, the light which was reflected by the object to be copied is exposed onto an image recording material so that an image is recorded. Accordingly, even if the object to be copied which is disposed on the platen glass is a three-dimensional object, the depth of the object can be copied to a certain extent.
However, when a three-dimensional object is copied by such a copying apparatus, the three-dimensional object disposed on the platen glass cannot be sufficiently covered by the platen cover. Therefore, on the recorded image, the background of the object to be copied is black. There is therefore room for improvement of the apparatus with respect to this point.
In this case, even if the three-dimensional object disposed on the platen glass is covered by a cloth or the like, the shadows of the cloth are recorded irregularly. This drawback is particularly noticeable in the copying of printed boards or in the copying of internal organs or the like in the medical field in which high-quality images are required.
A structure has been proposed in which a light box using a plurality of high-luminance lamps is used as a simple backlight, and the surface of the platen glass is illuminated by light in planar form. However, an extremely large amount of power is required, and the system is difficult to manage. Further, there are adverse effects due to the generation of heat (which presents a great problem when easily deformable objects, such as living organisms and the like, are copied). Therefore, this system as well did not result in a fundamental solution.